Brand new unit.. fully tested and ready to go. It has a couple of 'rough' spots, blemishes on the enclosure. We didn't want to try to pass this off as pristine. See pictures.  

MicroMASS 15w Attenuator

Designed for use with 10w amplifiers and lower. 5″ x 5″ x 2.25″

This attenuator has two knobs for tonal control. The main volume is controlled by the Lows-Mids knob. Then to control the treble, use the Mids-Highs knob. The treble control is always dependent on the main volume control. Be aware that the higher the setting on the main knob, the less the effect of the treble compensation. For instance, if you turn the main knob all the way to 10, you’ll notice very little change in the tone as you turn the treble compensation from one end to the other. The line out signal is dependent on your amplifier settings.

May be used on 4, 8, and 16 ohm amplifiers. Includes MASS bypass, and unbalanced line out. Two power level controls, one for the bass-mid frequencies and one for the upper mids-treble frequencies. They may be adjusted independently for the best tone at all levels of attenuation. These controls affect the actual signal going to the speaker, not the line out signal. So, it is like having high level tone controls. The controls are very effective and the tonal combinations are virtually infinite. Because a MASS motor is employed, a more realistic interaction between the attenuator and the output circuit of the amp occurs. The attenuation is continuously adjustable from -3dB to over -50db using the attenuation controls.

Like all Weber attenuators, setting the attenuation controls to minimum (maximum attenuation), allows the MicroMASS to be used as a dummy load for testing or for DI use.